Answer:
d) [25, 1.581]
Explanation:
The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean
and standard deviation(which is the square root of the variance)
, the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean
and standard deviation, which is also standard error,
.
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
In this question:

So the standard error is:

By the Central Limit Theorem, the mean is the same, so 25.
The correct answer is:
d) [25, 1.581]