1. Arrange the numbers $1, 2, 3, 4, 5$ in a row, with the last number being even, and ensure that the sum of any three consecutive numbers is divisible by the first of these three numbers. How many arrangements satisfy this condition?
(A) 8
(B) 9
(C) 10
(D) 11
- 1. C.

From the problem, we know that in three consecutive numbers, the first number can divide the sum of the last two numbers. Therefore, we first arrange the last digit and then test one by one from back to front. Thus, the numbers that meet the requirements are $54132, 14532, 35142, 43152, 23514$, $15324, 32154, 23154, 12354, 21354$, a total of 10 numbers.