How to remove deep stains from dishes<br>Wash dishes thoroughly. Leftover foodstuffs can cover up stains, shielding them from your cleaning efforts. Rinse and dry the dishes before continuing.
Can we infer the following?
carefully wash for 30 minutes

Available choices:
[a]. Yes.
[b]. It's impossible to say.
[c]. No.
The answer is:
[b].