Order of operations:
Parentheses/Grouping symbols
Exponents
Multiply/Divide (left to right)
Add/Subtract (left to right)
43-4÷2+5: There are not parentheses or exponents, so we move down to division. You must do the division first:
43-4÷2+5 = 43-2+5
Now there’s only addition and subtraction, so you do this left to right:
43-2+5 = 41+5 = 46
OK, so that doesn’t match any of your choices. Did you leave any parentheses out the expression?