Multi-choice problem: Continue writing the next sentence in this paragraph:

How to use a milk frother
Buy fresh milk.
Check the expiration date of milk when you buy it at the store. Choose milk that is farther from its expiration date.

pick from the following.
(a). Older milk has more glycerol, a natural compound that makes it harder for frothed milk to hold its bubbles. Use skim milk if you're new to frothing..
(b). To ensure that you are getting the right product, look for cans that have a seal from the expiration date listed on them. Often, these cans will be marked as " canned, " " mixed, " or " open..
(c). In some places, you can purchase fresh milk without any time in the store. Dairy and non-dairy milk products all have age-appropriate expiration dates, so you don't need to worry about them when shopping for a regular frother..
(d). Some dairy items may contain expired milk, which is more bitter than fresh. Make sure to choose plain, unflavored milk..
(a).