Which phrase gives the correct meaning of the upper case phrase in this paragraph?

jude planned on biking to the library. first he wanted to take a shower, but his sister had used all the hot water. then he was going to make a piece of toast, but his sister had eaten the last of the bread. when jude was leaving for the library, he couldn’t find his jacket. his mother told him his sister was wearing it and had taken his bike to go to the store. for jude, that was the last straw.

a.
how he started his day

b.
the end of his plans

c.
the final thing that made him lose his temper

d.
the thing that made him begin to feel very nervous