Answer:
The given polynomial has degree to be 4.
Explanation:
In a polynomial, the highest power of the variable in each term in it will be considered as the degree of that polynomial.
Here, the polynomial is

Here, both x and y are variables.
Hence, the maximum power of the term 3x² is 2.
And, the maximum power of the term
is 4.
And the maximum power of the term 3xy² is 3.
Therefore, the given polynomial has the degree to be 4. (Answer)