4. The fries had nearly 1,000 calories in them. Monica chose a salad instead.
 The most effective way to combine these sentences would be:
 a. The fries had nearly 1,000 calories in them, and Monica chose a salad instead.
 b. The fries had nearly 1,000 calories in them, but Monica chose a salad instead.
 c. The fries had nearly 1,000 calories in them, so Monica chose a salad instead.