Idioms
"to speak of the devil" A) to have an uncomfortable conversation / B) the person who you were talking about unexpectedly arrives / C) to talk about a person you don't like
B) the person who you were talking about unexpectedly arrives
"a piece of cake" to describe something A) very sweet / B) very fun / C) very easy
C) very easy
"to cost an arm and a leg" A) something cheap / B) something expensive / C) something of low quality
B) something expensive