Which of the following reagents reacts with benzaldehyde to produce $1$-phenylethanol?

The aldehydes which will not form a single Grignard product with one equivalent of Grignard reagent are:
$(a)$ Benzaldehyde
$(b)$ $4$-Formylbenzoic acid
$(c)$ $4$-Methoxybenzaldehyde
$(d)$ $4$-(Hydroxymethyl)benzaldehyde

Compound $(X)$ with molecular formula $C_4H_8O$ reacts with $2,4-DNP$ to form a derivative and gives a negative haloform test. The compound $(X)$ is:

Calcium butanoate on heating followed by treatment with $1,2-$ethanediol in the presence of a catalytic amount of an acid,produces a major product which is

In the presence of a dilute base,$C_6H_5CHO$ and $CH_3CHO$ react together to give a product. The product is

Assertion: Acetoacetic ester,$CH_3COCH_2COOC_2H_5$,will give iodoform test.
Reason: It does not contain $CH_3CO-$ group.