(b) the daily amount of calories that a rat eats increases steadily from birth to about age 3 months. then…

(b) the daily amount of calories that a rat eats increases steadily from birth to about age 3 months. then, the amount levels off until about age 6 months, when it increases again.
Answer
Explanation:
Step1: Analyze the description
The daily calorie - intake of a rat increases steadily from birth to 3 months, then levels off until 6 months and then increases again.
Step2: Match with graphs
The first graph has a continuous increase without a leveling - off period. The second graph has a decrease and then an increase which is not in line with the description. The third graph has a decrease after the leveling - off period which is incorrect. The fourth graph shows an initial increase, then a horizontal (leveling - off) part and then another increase which matches the description.
Answer:
The fourth graph (the one with an initial increase, a horizontal section, and then another increase)