Playing IMP’s, red on white, you pick up the following hand as dealer:

Spade Graphic K Q J 7 4, Heart Graphic K T 9 5 Diamond Graphic T 6 3 Club Graphic A.

You open 1Spade Graphic and see LHO bid 3Club Graphic, partner calls 4Club Graphic, and RHO bids 6Club Graphic.

What do you call and why? In particular, does your action refer to hand quality, clubs, or both?