Q: Given a math problem with context and a question and 5 answer choices, the task is to provide the correct answer choice based on the problem. You must choose one of the given answer choices by letter: a, b, c, d, or e; anything else is invalid.
Problem: a man swims downstream 90 km and upstream 55 km taking 5 hours each time; what is the speed of the current ?
Options: a. 3.8, b. 3.5, c. 3.3, d. 3.2, e. 1.6
A:
b