daily chinese Test: Should Dan Express His Love to Lily?

Beginner Level 初级 (chūjí)
Conversation:

Wǒ yào xiàng Lily biǎobái.
Dan: 我 要 向 Lily 表白。
Qù ba, wǒ tǐng nǐ.
Frank: 去 吧，我 挺 你！
What does “挺 (tǐng)” mean in this sentence?
A: quite/very
B: To stand upright
C: To support

See answer at http://resources.echineselearning.com/minitestanswers/minitestanswers-chinese-695.html?ecl=ptEEEEEEpg081603