To study or not studying

My question is as I have chosen to do 4 A levels and I figured out it was too much to handle as my mock grades were Bio C,Chem U ,Psychology E and English lit B and considering my target grade is a B, I am obviously going to drop a subject. But where my problem comes in is that I would want to drop Chem, and carry on with bio psychology and eng lit,as I got the lowest grade in it I’m worried that they’ll tell me that somehow I’m not allowed to do this. And the thing is that I haven’t studied for chemistry that hard and if they were going to tell me this I would be in uh big trouble. What do you think I should do study for it just in case they’ll tell me psychology as a course is it too full and thus I need to carry on with chem or to no worry as they can’t force me to do a subject I don’t want to?

Do NOT do 4. It's not worth it

Yeh I kinda did not know what I was getting my self into when starting year 12 and doing 4 A levels but yeh im going to definitely going to drop chem but I have a question, they cant force you to carry on with a subject when you dont want to?