HELLO ALL. MORNING.

i was looking through the combination choices and im now so irritatingly stuck between choosing. but C2 is a must take for me, so thats choice number one. A2 is like a backup so i left it number three. but i cant think of what to put under the second one. im stuck between C3 and C4 and A1. so all friends, what are your choices? i could use them as reference :[)