Find the first arithmetic mean between 100 and 135 given the following sequence:

..., 100, ___, ___, ___, ___, 135, ...
A. 107
B. 114
C. 121
D. 128

d = (135-100)/5 = 7

100+7 = 107

To find the first arithmetic mean between 100 and 135, we can calculate the average of these two numbers.

Step 1: Add the two numbers together:
100 + 135 = 235

Step 2: Divide the sum by 2:
235 / 2 = 117.5

Since the number should be an integer in this arithmetic sequence, we need to round it to the nearest whole number.

Step 3: Round 117.5 to the nearest whole number:
117.5 rounds up to 118

Therefore, the first arithmetic mean between 100 and 135 is 118.

Looking at the answer choices, none of them match our calculated result of 118. Therefore, none of the given options (A, B, C, D) are correct.