Which one of the following statements is not correct?

Consider the following.

Assertion (A) Phosphorus can form both phosphorus (III) and phosphorus (V) chlorides but nitrogen cannot form nitrogen (V) chloride.

Reason (R) The electronegativity of nitrogen is more than that of phosphorus.

The correct answer is

The correct statements about the compounds of boron are

I. In borax bead test, the colour of cobalt metaborate is blue.

II. Diborane is prepared by the oxidation of sodium borohydride with iodine.

III. In diborane oxidation state of hydrogen is +1 .

IV. Boric acid is a tribasic acid.

An oxoacid of phosphorus ' $X$ ' reduces silver nitrate solution to metallic silver and gets oxidised to another compound $Y . X$ and $Y$ respectively are