The correct option is A 5
For finding the degree of an expression in more than one variable, we consider the sum of the exponents of the variables in each term and then take the highest of those as the degree of the polynomial.
Here,
the sum of exponents of variables of the term 4x2y3 = 2+3= 5,
the sum of exponents of variables of the term 2xy3 = 1+3= 4,
the sum of exponents of variables of the term 3x2y = 2+1= 3.
Hence, the degree of the polynomial is 5.