What should come next in the series of odd numbers: 1, 3, 5, 7?

The series of numbers given is a sequence of consecutive odd numbers. The pattern begins with 1 and continues by adding 2 to get the next number in the sequence:

• Starting with 1, adding 2 gives us 3.
• Then, adding 2 to 3 results in 5.
• Continuing this pattern, adding 2 to 5 results in 7.

Following this established pattern, the next number after 7 would be obtained by adding 2 again, which results in 9. This is why the correct answer is that the next number in the series is 9, as it is the next odd number following the sequence of increasing odd numbers.