BASIC Issues

I've tried everything I possibly can and this code still doesn't function properly. Could someone please fix it, I would greatly appreciate it.
Here is the code:
REM Basic RPG!

PRINT "You are walking along a path when you stumble upon a sword."
ENDIF 

INPUT " Do you: (A) Keep walking.     (B) Pick up the sword. (C) Stop and examine the sword. ", choice

IF choice = A THEN
    PRINT "Your life continues as normal, and you live a long and happy life."
ELSE    
    IF choice = B THEN
        PRINT "You feel a surging feeling coursing through your veins. You begin to feel weak."
        INPUT "Do you: (A) Drink your potion. (B) Tough it out. (C) Other.", choice
        IF choice = A THEN 
            PRINT "Thankfully, the potion works and you continue on your journey feeling fine and in possesion of a brand new sword!"
        ELSE PRINT "You begin to feel strange and painfully transform into a platypus."
        ENDIF
        
        

I haven't added choice c yet, but it won't even work properly as is. When I type b, all it does is print what it is supposed o print for a.

I don't really know anything about this language, but maybe
ELSE
    IF choice = B THEN
Should be
ELSEIF choice = B THEN
     PRINT "You feel a ..."
Or maybe it's an issue with A and B, maybe they should be in quotes IF choice = "B" THEN since you're taking string as input?

that language...that accursed tongue...runnnn, flyy you fool!

>> 1
BASIC Issues
Back to /g/, please.