Re-write this sum using sigma notation...?

Question

4/5 + 5/6 + 6/7 + 7/8 + 8/9 + 9/10

When it's the number on top of sigma and the number below, just write:

Is it:

A.) 5 / SIGMA / k = 1 3 + k / 4 + k

B.) 6 / SIGMA / k = 1 3 + k / 5 + k

C.) 6 / SIGMA / k = 1 4 + k / 5 + k

D.) 6 / SIGMA / k = 1 3 + k / 4 + k

I hope you can figure out my notation here, I think the sigmas are kind of hard to write, but just imagine the numbers before SIGMA are the numbers on top if written correctly, and the ones to the left are the ones on the bottom. The numbers to the left are waht is multiplied.

Answer 1

4/5 + 5/6 + 6/7 + 7/8 + 8/9 + 9/10 =

6
∑(k + 3)/(k + 4)
k=1

Answer 2

The answer is D

6
{Sigma} (k+3)/(k+4)
k = 1

Hope this makes sense and is helpful :)