Answer:
(6 + m²)(6 + m²) . . . . . . . lower left selection
Step-by-step explanation:
When in doubt, you can multiply out the offered factorizations and see which one gives you the given expression.
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A lot of math is about pattern matching. The given trinomial has first and last terms that are perfect squares. The first term is the square of 6. The last term is the square of m². The middle term is double the product of these two square roots: 2·(6m²) = 12m².
This pattern matches the special form of the square of a binomial:
(a + b)² = a² + 2ab + b²
This special form is useful to commit to memory (at least while you're in math classes in school).
So, when you see 6² + 2·6·m² + (m²)², you can recognize that it is the square ...
(6 + m²)²
When this is written out in the way the answer choices are written, it looks like ...
(6 + m²)(6 + m²)
