The correct answer is 5.
The missing number is the number that completes the sequence. The sequence is a series of numbers that are each 1 less than the previous number. Starting with 8, the sequence is 8, 7, 6, 5, 4, 3, 2,
1.Option A, 8, is not the missing number because it is not 1 less than the previous number in the sequence.
Option B, 6, is not the missing number because it is not 1 less than the previous number in the sequence.
Option C, 5, is the missing number because it is 1 less than the previous number in the sequence.
Option D, 7, is not the missing number because it is not 1 less than the previous number in the sequence.