When acetaldehyde is heated with Tollen's reagent,what is obtained?

The major product formed in the following reaction is:
$CH_3CHO + PhCOCH_3 \xrightarrow{\text{dil. } NaOH}$

Which of the following compounds will give a positive test with Tollen's reagent?

Write a note on the electrophilic substitution reaction of aromatic aldehydes and ketones.

Which of the following compounds will not undergo tautomerism?

Given below are two statements:
Statement $I$: Cross aldol condensation between two different aldehydes will always produce four different products.
Statement $II$: When semicarbazide reacts with a mixture of benzaldehyde and acetophenone under optimum pH,it forms a condensation product with acetophenone only.
In the light of the above statements,choose the correct answer from the options given below: