什么 (Shénme): what.
几 (Jǐ): a few; several; some. (几个 jǐ gè how many?).
怎么 (Zěnme): how.
几点 (Jǐ diǎn): what time.
Zhèr de bāozi hěn hào chī, nǐ yào chī jǐ gè?
A: 这儿 的 包子 很 好吃，你 要 吃 几 个？
The steamed stuffed buns are delicious here. How many do you want to eat?
Wǒ yào chī liù gè.
B: 我 要 吃 6 个。
I want six.
According to the answer “6个 (liù gè),” we see that the question is asking “几个 (jǐ gè) how many.” So B is the correct answer.