This cropped up in a handicap club game, but the colours have been reversed because I got confused when I was putting the SGF file together.
The rest of the board is essentially settled -- I have omitted it because I cannot remember how it was. M8 and friends are definitely alive (2 real eyes), and there is a living black group (possibly the same one) out towards K6.
I do not want to synthesise the position on the rest of the board, because I would end up creating something stupid that would detract from the original problem.
(;GM[1]FF[4]CA[UTF-8]AP[CGoban:2]ST[2]
RU[Japanese]SZ[19]KM[0.00]
PW[White]PB[Black]AW[nl][ol][mm][om][on][qn][po][lp][qp][lq][mq][nq][oq][pq][qq]AB[mk][ll][ml][nm][ln][nn][oo][mp][np][op][pp]LB[ql:T]TR[mm]C[White has just played into your mouth shape with 1. You can tenuki for 8 points in gote (play at T). Choose the best play!]PL[B]
(;B[mn]LB[mo:A]CR[mn]C[Close: Your stones are safe, but white still has a 10-point ko threat at A. You can do better.])
(;B[lm]CR[lm]
;W[mo]CR[mo]
(;B[mn]CR[mn]
;W[no]CR[no]C[Lose 10 points but keep sente. White comes out ahead.])
(;B[no]CR[no]
;W[mn]CR[mn]C[Are you insane!?!?!? Seriously, don't do that unless you really, really need a 16-point ko threat.]))
(;B[ql]CR[ql]
;W[mo]CR[mo]
(;B[mn]CR[mn]
;W[no]CR[no]C[Lose 10 points but keep sente. White comes out ahead.])
(;B[no]CR[no]
;W[mn]CR[mn]C[Are you insane!?!?!? Seriously, don't do that unless you really, really need a 16-point ko threat.])
(;B[lm]CR[lm]
;W[mn]CR[mn]C[Lose 14 points but keep sente, white has come out ahead]))
(;B[mo]CR[mo]C[RIGHT
You saved all your stones, and the biggest ko threat white has is (N6) 4 points.])
(;B[lo]CR[lo]
;W[mo]CR[mo]
;B[mn]CR[mn]
;W[no]CR[no]C[Lose 10 points but keep sente. White comes out ahead.]))