What will be the decreasing order of basic strength of the following conjugate bases? $${ }^{-} \mathrm{OH}, \mathrm{R} \overline{\mathrm{O}}, \mathrm{CH}_3 \mathrm{CO} \overline{\mathrm{O}}, \mathrm{Cl}$$

Given below are two statements :

Statements I : Acidity of $$\alpha$$-hydrogens of aldehydes and ketones is responsible for Aldol reaction.

Statement II : Reaction between benzaldehyde and ethanal will NOT give Cross - Aldol product.

In the light of the above statements, choose the most appropriate answer from the options given below :

Match List I with List II :

	LIST I Mechanism steps		LIST II Effect
A.		I.	$$-$$ E effect
B.		II.	$$-$$ R effect
C.		III.	$$+$$ E effect
D.		IV.	$$+$$ R effect

Choose the correct answer from the options given below :

Identify B and C and how are A and C related?