男性，30岁。肛门胀痛，逐渐加重，伴畏寒发热3天。查体：左侧肛周皮肤稍红，指诊发现距肛门4cm左侧偏后有明显压痛、肿胀。首先应考虑的是哪种直肠肛管周围脓肿（）

A.骨盆间隙直肠脓肿

B.直肠壁内脓肿

C.肛门周围脓肿

D.坐骨直肠间隙脓肿

E.括约肌间脓肿

After problems are posed, we should sort them out, ______ the advantages and disadvantages and decide what to do.

A．weigh

B．think

C．range

D．examine