It's a vocabulary question, so what you need to do is to know what the vocabulary means:
el banco is the bank
1) llenar el tanque - fill the tank ( you would go to a gas station for that)
2) echar una carta - send a letter (you would go to a post office for that)
3) cobrar un cheque - collect a check, yes, you would go to el banco, this is the correct answer!
4) ir a pie - go on foot. It's not necessary to go to a bank to do that!
