19) A

When the universe was formed, it was filled with electromagnetic radiation in the form of intense gamma-rays. Now it is in the microwave region of the spectrum.

If you remember the electromagnetic spectrum, you will know that frequency decreases as we shift from gamma to microwave and wavelength increases. So, statements 1 and 2 are wrong.

Also, frequency is indirectly proportional to wavelength. So, statement 3 is also wrong.