Ozonolysis of alkenes followed by reaction with zinc dust and water gives a mixture of aldehyde and ketone products, depending on the substitution pattern of the alkene.

1. Ozonolysis of Alkenes:
- Ozonolysis is a chemical reaction that breaks the carbon-carbon double bond in alkenes using ozone (O3). It involves the addition of ozone to the double bond, followed by a reductive workup to cleave the bond and form two carbonyl compounds.
- The reaction can be represented as:
R1R2C=CR3R4 + O3 → R1R2C=O + R3R4C=O
- Here, R1, R2, R3, and R4 represent different groups attached to the carbon atoms.

2. Reaction with Zinc Dust and Water:
- After ozonolysis, the resulting carbonyl compounds can further react with zinc dust and water in the presence of an acid catalyst, such as hydrochloric acid (HCl).
- The reaction is a Clemmensen reduction, which involves the conversion of carbonyl compounds into the corresponding alkanes through a reduction process.
- The reaction can be represented as:
R1R2C=O + Zn + HCl → R1R2CH2 + ZnCl2 + H2O

3. Product Formation:
- The substitution pattern of the alkene determines the nature of the products formed.
- If the alkene is a symmetrically substituted alkene, meaning that the substituent groups are the same on both sides of the double bond, then the ozonolysis will yield two identical carbonyl compounds. The subsequent reduction with zinc dust and water will give a single product, which is a ketone.
- If the alkene is unsymmetrically substituted, meaning that the substituent groups are different on each side of the double bond, then the ozonolysis will yield two different carbonyl compounds. The subsequent reduction will give a mixture of aldehyde and ketone products.
- Therefore, depending on the substitution pattern of the alkene, the reaction sequence of ozonolysis followed by reaction with zinc dust and water can give either a ketone (symmetrical alkene) or a mixture of aldehyde and ketone (unsymmetrical alkene) as the final products.

In conclusion, the correct answer is option 'D' - All of these, as the products obtained from the reaction sequence depend on the substitution pattern of the alkene.