This is a test of commonsense with single/multi-choices. Complete the next sentence:

How to wash acrylic fibers
Pretreat any stains.
You can't rely on detergent alone to get out a big stain on your acrylic clothes. Hit the spot with a spray stain remover and rub the remover in with your fingers so you know it's really worked in the fabric.

Choose from:
[1]. Since acrylic fabric is a delicate fabric, you can use a different type of stain remover. The process will take longer if the stain is old and still in the fabric, and there won't be a residue from it on the acrylic pieces.
[2]. Don't forget to spray the stain remover on the inside of the clothing too. If it's a really old or stubborn stain, try scrubbing the remover in lightly with an old--but clean--toothbrush.
[3]. Soak your acrylic in warm, soapy water for 2-3 minutes before rinsing. This helps spread the remover and protect your clothing and the fibers from stain drippings.
[4]. It will probably turn the stain white or orange. Other acrylic stains will require a little prep before they can be scrubbed.
The answer is:
[2].