Number of complexes from the following with even number of unpaired "$$\mathrm{d}$$" electrons is ________ $$[\mathrm{V}(\mathrm{H}_2 \mathrm{O})_6]^{3+},[\mathrm{Cr}(\mathrm{H}_2 \mathrm{O})_6]^{2+},[\mathrm{Fe}(\mathrm{H}_2 \mathrm{O})_6]^{3+},[\mathrm{Ni}(\mathrm{H}_2 \mathrm{O})_6]^{3+},[\mathrm{Cu}(\mathrm{H}_2 \mathrm{O})_6]^{2+}$$ [Given atomic numbers: $$\mathrm{V}=23, \mathrm{Cr}=24, \mathrm{Fe}=26, \mathrm{Ni}=28 \mathrm{Cu}=29$$]

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 :