Which compound undergoes the iodoform reaction?

The reaction sequence is as follows:
Benzene + $CH_3COCl$ $\xrightarrow{\text{Anhydrous } AlCl_3} (A)$ $\xrightarrow{(x)} \text{Ethylbenzene}$.
Reagent $(x)$ can be:

Iodoform test is not given by

Acetyl bromide reacts with excess of $CH_3MgI$ followed by treatment with a saturated solution of $NH_4Cl$ gives:

Which of the following reagents can react with both aldehydes and ketones?

$CH_3CHO \xrightarrow{LiAlH_4} CH_3CH_2OH$
Which nucleophile is added in this reaction?