Final answer:
There are infinite lengths between 333.3 and 354.1 days because the real number system is dense, allowing for an infinite number of decimal values between any two distinct numbers. Option A is correct.
Step-by-step explanation:
The question asks how many different lengths of time can exist between 333.3 and 354.1 days. The answer to this question is infinite, as there are an infinite number of decimal values between any two distinct numbers on the number line, no matter how close these numbers are to each other. This is true because the system of real numbers is dense, meaning between any two different real numbers there are infinitely many other real numbers.
The number of lengths between 333.3 and 354.1 days can be determined by finding the difference between the two lengths. Subtracting 333.3 from 354.1 gives us 20.8. So, there is one length between these two numbers.