Please note that there is ko at S12 and the rest of the board is settled in a common way. That means there are some threats for both, but because you are in byoyomi you don't know if you have more of them than your opponent. There are no points to take on the unshown part of the board. -> More points are always better, having a better chance to win the ko is your secondary goal. Sente is not important.
(;AW[rq]AW[rp]AW[qp]AW[po]AW[pn]AW[rl]AW[sl]AW[qm]AW[rn]AW[qn]AB[ql]AB[qk]AB[pm]AB[om]AB[on]AB[oo]AB[op]AB[pp]AB[qo]AB[rr]AB[qr]AW[sr]AB[so]AB[rj]AB[sj]AB[qj]AW[sh]AW[sg]AW[rg]AW[qg]AW[qh]AB[qi]AB[si]AW[ri]AB[pl]AB[qs]AB[pr]AB[or]AB[nr]AB[mr]AB[lq]AB[lp]AB[mo]AB[no]AW[qq]AW[oq]AW[pq]AW[nq]AW[mq]AB[lr]AB[lo]C[Common endgame. Black just played the marked stone, white to play.]TR[so]AP[goproblems]
(;W[ro]C[Locally this is a good answer, but you could do slightly better ;-)])
(;W[sn];B[sq];W[sp];B[rh]C[Now you still have to add one more stone to your territory, so you end with seven points only. One point worse than the solution plus black takes the ko.])
(;W[sp];B[rh]C[You will still have to play S5 and have seven points only, one point plus the ko worse than the solution.])
(;W[sq]C[Locally correct, keeping eight points.. but you could do a bit better with the ko :)])
(;W[rh]C[Yes, black T5 was just a neutral point. No matter what black plays in the white group nex tit will be always possible to live with eight points :)RIGHT]))