Final answer:
The question asks which number is irrational, but among the given options, none are correctly represented as irrational numbers. Only square roots of non-perfect squares are considered irrational numbers.
Step-by-step explanation:
The question is asking which number from the provided options is an irrational number.
An irrational number is a number that cannot be expressed as a simple fraction - that is, its decimal form is non-terminating and non-repeating. Option A (40) and option B (49) are both integers and can therefore be written as a fraction (40/1 and 49/1 respectively), so they are not irrational. The symbol for option C looks like a typo, but interpreted as the square root of zero (√0), this is equal to 0, which is a rational number for the same reason as 40 and 49.
Option D seems to be a typo as well and can be ignored.
In general, square roots of non-perfect squares are irrational, so if there were an option like √2 or √3, they would be irrational numbers. However, based on the given options, none are correctly represented as irrational numbers.