Can you explain how you got the answer as well please?

The answer is option A

Step-by-step explanation:

I have shared a file with the steps if you still can't understand so feel free to contact me through my email. Thanks.

The standard deviation of the data set will be found as follows:
10, 10, 15, 20, 25
mean=(10+10+15+20+25)/5=80/5=16
next we find the:
∑(x-μ)²
where:
μ- mean
thus
∑(x-μ)²=[(10-16)²+(10-16)²+(15-16)²+(20-16)²+(25-16)²]=206
hence the variance will be:
Var(x)=∑(x-μ)²/(n-1)
=206/(4-1)
=51.6
thus the standard deviation will be:
σ=√51.6
σ=7.176