1. Given the set $M=\{1,2,3, \cdots, 10\}, A$ is a subset of $M$, and the sum of the elements in $A$ is 8, then the number of subsets $A$ that satisfy the condition is ( )
A. 8
B. 7
C. 6
D. 5
Solution: C.
Subsets $A$ with an element sum of 8 are: $\{8\},\{1,7\},\{2,6\},\{3,5\},\{1,2,5\}, \{1,3,4\}$, a total of 6.