Final answer:
The irrational numbers in the given options are 9π and the square root of 12.
Thus, the correct option is A.
Step-by-step explanation:
From the given options, the irrational numbers are 9π and the square root of 12. Irrational numbers cannot be expressed as a fraction or a decimal and they have non-repeating and non-terminating decimal expansions.9π is irrational because π is irrational, and the square root of 12 is irrational because √12 cannot be simplified to a fraction or a terminating decimal.
Therefore, option A, which includes 9π and the square root of 12, is the correct answer.