Correct option is A
Blessing in disguise: Something that seems bad at first but turns out to be good later.
Sentence use:
Losing that job turned out to be a blessing in disguise — it pushed me to start my own business.
Similar idioms:
Silver lining – A positive aspect in a negative situation.
Every cloud has a silver lining – There is always hope or something good in a bad situation.
Turn the tables – To change a bad situation into a good one or to reverse the outcome.