CH₃CH₂OH (ethanol) reacts with CH₃MgBr (methyl magnesium bromide) to form P.
P undergoes a reaction with conc. H₂SO₄ (concentrated sulfuric acid) to form Q.
Q reacts with B₂H₆ (diborane) and H₂O₂ / OH⁻ to form R.
Analysis of compounds P and R:
Step 1: The reaction between CH₃CH₂OH and CH₃MgBr forms a Grignard reagent intermediate. This would typically lead to the formation of ethyl methyl ketone (acetone) in Step 1, which would be compound P.
Step 2: P, being an aldehyde or ketone, undergoes acidic dehydration (likely via concentrated H₂SO₄) to form an alkene. The reaction produces Q.
Step 3: The B₂H₆ and H₂O₂/OH⁻ reaction indicates a hydroboration-oxidation reaction, converting the alkene Q into R (which could be an alcohol).
Type of Isomers:
Since both P and R differ in the position of functional groups (as seen from their formation through different steps), they are position isomers.
Conclusion:
The compounds P and R are position isomers.
Thus, the correct answer is Option C: Position isomers.
are isomeric compounds. 
are functional group isomers.