You can ( ) yourself to some Italian spaghetti after working in the garden.

C
help yourself to sth...
enjoy+some italian spaghetti
or enjoy yourself.
cook+some italian spaghetti

A
enjoy oneself=have a good time.过得愉快
这里是习惯,喜欢的意思

C
help oneself to指的是多吃点的意思
整句话的意思是:你应该在花园工作以后多吃一些意大利细面条

A enjoy oneself 快乐
help...to do sth.
所以选择enjoy

绝对是C ，初中时就学过的，Help yourself to some fish!!意思是别客气，随便吃点... 是个日常用语