Task: Question Answering
Input (English): Problem: tabby is training for a triathlon. she swims at a speed of 1 mile per hour. she runs at a speed of 7 miles per hour. she wants to figure out her average speed for these two events. what is the correct answer for her ?
Options: a. 8 mph, b. 5.25 mph, c. 3.5 mph, d. 4 mph, e. 0.5 mph
Output (English): d