Final answer:
The correct answer to find the population after 30 minutes using the function f(t) = 3e^t is A) 3e^0.5, since 30 minutes is equivalent to 0.5 hours.
Step-by-step explanation:
To find out the population of a strand of bacteria after 30 minutes using the exponential growth function f(t) = 3et, where t is time in hours, we need to convert 30 minutes into hours. Since 30 minutes is half an hour, we use 0.5 as the value of t for the calculation. Therefore, the function will become f(0.5) = 3e0.5.
The correct answer is A) 3e0.5, as none of the other options provide the correct calculation for 30 minutes (or 0.5 hours). Options B) and C) incorrectly interpret the time variable, and option D) suggests a time period of 15 minutes (or 0.25 hours), which is not what the question asks.