Let R and T be points respectively on sides [BC] and [CD] of a square ABCD with side length 6 such that ∣CR∣+∣RT∣+∣TC∣=12. What is tan(RAT)<spanclass=′latex−bold′>(A)</span>23<spanclass=′latex−bold′>(B)</span>3<spanclass=′latex−bold′>(C)</span>31<spanclass=′latex−bold′>(D)</span>21<spanclass=′latex−bold′>(E)</span>1