44. No.1 piston ring sticks to ring groove owing to excessive cylinder lube oil.
选项：

A:
A: There are some carbons in the piston crown. ;
B:
B: There are several piston rings in the ring grooves. ;
C:
C: Several piston rings are seized because of poor lubrication. ;
D:
D: Several piston rings are seized because of excessive lube oil.