The first term of the series is c) 35.
Here's the step by step explanation:
1. We don't have enough information to determine the pattern of how the terms are decreasing from 8 to 0 and then repeating.
2. Therefore, we can't use an explicit formula to find the first term.
3. However, we can make an observation: Each subsequent term is 5 less than the previous term.
4. If the second term is 8, then the first term must be 5 more than that, which is 8 + 5 = 35.
Therefore, option c) 35 is the correct answer. The other options (15, 25, and 45) do not follow the pattern of decreasing by 5 each time.