Enzymes

Enzymes are biocatalysts, are very specific for a particular reaction and substrate, and (like chemical catalysts) reduce the activation energy of the process. Enzymes are proteins in nature, not polysaccharides – so this statement is incorrect.

Proteins are polymers of amino acids joined by peptide bonds; enzymes that hydrolyse peptide bonds are called proteolytic enzymes.
Pepsin, present in the gastric juice of the stomach, hydrolyses proteins into smaller polypeptides (proteoses and peptones).
Trypsin, present in the pancreatic juice, acts in the small intestine and breaks the polypeptides down further, finally giving amino acids.
Amylase and diastase act on starch, and maltase acts on maltose.
Lipase acts on fats.
Invertase hydrolyses sucrose, and zymase converts glucose into ethanol.
So enzyme (A) is pepsin and enzyme (B) is trypsin.

Triglycerides (fats and oils) are esters of glycerol with three fatty acid molecules.
Lipase catalyses their hydrolysis: triglyceride $+ 3H_2O \xrightarrow{lipase}$ glycerol $+ 3$ fatty acids.
Zymase converts glucose into ethanol and $CO_2$; pepsin hydrolyses proteins into peptides; maltase hydrolyses maltose into glucose.
So the enzyme is lipase.

Almost all enzymes are globular proteins.
Each enzyme has a specific three-dimensional structure, which forms an active site that fits only particular substrates. This specific structure is responsible for the high specificity of enzyme action.
If the structure is destroyed (denaturation by heat or pH change), the enzyme loses its activity.
So enzymes are made up of proteins with specific structure.

Diastase (amylase) is an enzyme that hydrolyses starch into maltose; it is found in germinating barley (malt). Correct.
Cycloheptane is a saturated cyclic alkane, not aromatic (aromatic compounds are planar, cyclic and conjugated with $(4n + 2)\pi$ electrons).
Acetophenone, $C_6H_5COCH_3$, is a ketone, not an ether.
So the correct statement is that diastase is an enzyme.