Hydrolysis of an ester gives acid $A$ and alcohol $B$. $A$ reduces Fehling solution and oxidation of $B$ gives $A$. The ester is

Product $(A)$ and $(B)$ respectively in the above reaction are

Which is the major product of the following reaction?

Given below are two statements:
Statement $I:$ Ethyl pent$-4-$yn$-$oate on reaction with $CH_{3}MgBr$ gives a $3^{\circ}$ alcohol.
Statement $II:$ In this reaction,one mole of ethyl pent$-4-$yn$-$oate utilizes two moles of $CH_{3}MgBr$.
In the light of the above statements,choose the most appropriate answer from the options given below:

The correct order of acid strength of the following carboxylic acids is $-$

$(i) \ F_3CCOOH$
$(ii) \ CH_3COOH$
$(iii) \ C_6H_5COOH$
$(iv) \ CH_3CH_2COOH$
Correct order of $pK_a$ value is: