PASCAL 2023 Problem 8

A sign has 31 spaces on a single line.
The word RHOMBUS is written from left to right in 7 consecutive spaces.
There is an equal number of empty spaces on each side of the word.
Counting from the left, in what space number should the letter \mathrm{R} be put?

Answer Choices
A. 12
B. 13
C. 14
D. 15
E. 16