When we multiply a number with a number less than 1 then the result will always smaller than the original number.
For example: 4* 0.5 =2
Here 0.5 is less than 1. So, when we will multiply 0.5 with 4 then we got the result 2 which is smaller than 4.
If denominator is bigger than the numerator then that number will be less than 1.
So, 2/7 is less than 1 because 7 is more than 2.
Similarly 3/8 is also less than 1.
So, Choice B is not correct as it says 2/7>1.
Let's check the other choices now.
A. 2/7 times 3/8 < 3/8 because 2/7 < 1
Multiply the numerators and denominators.
0.1<0.375
Above inequality satisfy.
So, A is the correct choice.
C. 2/7 times 3/8< 2/7 because 3/8 < 1
0.1<0.286
This inequality also satisfy. So, C is also correct.