What are BCP 38 （Best Common Practices 38）/RFC 2827 Ingress Packet Filtering Principles？（）A、Filter Smurf ICMP packets.B、Filter as close to the core as possibleC、Filter as close to the edge as possibleD、Filter as precisely as possibleE、Filter both source a

资料：China's Fosun has offered to buy almost 17 percent of Millennium BCP, Portugal's largest listed bank, and potentially lift its stake to 30 percent, following a having in its share price in the year to date.
BCP said in a regulatory filing late on Saturday that Fosun Industrial Holdings had offered to pay ?0.02 a share, equal to Friday's closing price, in a private placement of 16.7 percent of the bank's share capital. According to the filing, Fosun was also considering increasing its shareholding to “20-30 percent”.
Fosun, one of China most acquisitive companies, made its Millennium BCP offer a week after it agreed to pay $1.1bn for 86 percent of Indian drugmaker Gland Pharma. In recent years, it has also snapped up France's Club Med and the top Portuguese insurer in Europe.
Analysts deem BCP to be in need of capital and vulnerable to a takeover after its share price fell from ?0.05 earlier this year, pushing its market value to a little over ?1.1bn.
In a recent report on Portugal's undercapitalisted banks, which are heavily burdened by bad debts, Barclays said BCP could need a capital increase of about ?2bn.
On Friday, the bank posted a ?197.3m loss for the first half of 2016, down from a profit of ?240.7 for the same period last year. But it said that stress tests by the European Banking Authority had shown it had sufficient capital to withstand a financial crisis. Under the tests, BCP had a common equity tier one ratio-a key measure of capital strength-of 6.1 per cent under stressed conditions, above the 5.5 per cent threshold seen as the minimum adequate level.
Fosun has now offered to subscribe to a private placement, reserved solely for the Chinese group, that would give it a 16.7 percent stake in BCP. It said it was “also considering increasing its stake through secondary market acquisitions or in the context of future capital increases” to up to 30 percent.
This offer, which is subject to regulatory approval by Portuguese and EU authorities, is conditional on Fosun being able to appoint at least two of the 20 BCP board members, and up to five members in the event of increasing its stake.
BCP said it recognized “the strategic potential” of Fosun's offer, saying it would swiftly proceed with an analysis of its “many positive aspects” before making a recommendation to its board of directors.

In paragraph four, what does the word “vulnerable” mean?

A.Nonchalant
B.Susceptible
C.Averse
D.Neutral