Tina can't see the blackboard because the boy who sits _________ her is very big and tall. [ ]

A. behind

B. in front of

C. next to

旅客自上海至厦门旅行，申报一件行李，价值为5400元人民币，重量为3kg。请问旅客需要缴纳那些费用并计算旅客应缴纳多少费用。（SHA-XMN经济舱票价800元，请写出计算过程）