Which best serves as the title for the passage?

Câu hỏi: Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 44 to 50
There is a poem in Sanskrit, the classical language of India, which says that friendship must consist of the following elements: giving, taking, sharing secrets, knowing where your friends are, and giving and sharing food with them. This ancient definition seems like a very apt description. Shared interests and opinions are essential. It isn't easy to get on with someone who can't stand your taste in music or fashion.
Most of us have friends - but it's likely that only a few of them can be described as close friends. Robin Dunbar, a British professor of evolutionary psychology, believes that the maximum number of people we can have in our social group at one time is 150. Many of these are acquaintances. We don't meet them very often, but we might invite them to a big party, for instance. But - according to Dunbar - we don't normally have more than five close friends.
So, who is a best friend? It is someone who's there for you when you're feeling miserable - to give you advice when you want it and to just listen when you need someone to talk to. It might be someone you have known all your life, or someone you've recently met. It might be someone you only see once a year, but when you do get together it feels like you saw him or her only last week. But can you have a best friend of the opposite sex? In theory, the answer should be yes, but in practice, things can get complicated!
These days, social networking sites offer many opportunities to get to know people online. These are usually people who are into the same things as you are (such as music and films), and can give you advice about the different issues you face. For some people, especially those who aren't so self-assured, making friends online is easier. Online friends aren't going to be as demanding as your friends from the real world might be. Moreover, if you get bored with a conversation online, or if someone's messages are getting on your nerves, you can just ignore them. On the other hand, it may not be realistic to expect your online friends to give you real support when you need it - so a balance of online and real-world friends is probably ideal!
Which best serves as the title for the passage?
A. Is a Friend in Need a Friend Indeed?
B. What are Friends for?
C. Online Friends: Old but Gold!
D. Fewer Friends, Less Satisfaction?