Answer:
(C)

Explanation:
Let
represent the number that is unknown.
Using the words, we can write out each equation.
"The sum of three times a number and seven" will be adding 7 to 3x. So
.
"is greater than four times the number." will include a greater than sign and then 4 times the number, x. So:

Combining these, we get
.
Hope this helped!