Which of the compounds with molecular formula $C_5H_{10}$ yields acetone on ozonolysis?

The rate of hydration of the following compounds will be in the order:

$P$ is obtained by reductive ozonolysis of which of the following compounds? The reaction is given as:
Cyclohexanone + Acrolein $\xrightarrow{\text{OH}^-, \Delta} P$ (dicarbonyl compound) $(mf = C_{10}H_{14}O_2)$

The alkene that gives only acetone upon ozonolysis is .......

Propanal and pentan-$3$-one are the ozonolysis products of an alkene. What is the structural formula of the alkene?

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R.$
Assertion $A :$ Treatment of bromine water with propene yields $1-$bromopropan$-2-$ol.
Reason $R:$ Attack of water on bromonium ion follows Markovnikov rule and results in $1-$bromopropan$-2-$ol.
In the light of the above statements,choose the most appropriate answer from the options given below: