Find the mistake: In case it will rain hard this afternoonyou should take the raincoat with You.
it will rain
The following clause has the conjugation verb “should + V-infinitive” type 1 conditional sentence structure
In case + S + V-present: in case, in case
Edit: it will rain → it rains
=> In case it rains heavily this afternoon, you should bring a raincoat.
→ Choose the answer C