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

How to buy propane
Determine what your propane tank is for.
Whether you purchase a propane tank or lease one, the best way to start narrowing down your choices is by asking yourself what you need propane for. It can be used for drying clothes, heating your home, and cooking, among other things.

OPT: a. Without all of that, your tank will probably not be able to provide adequate oxygen. Think about what it will be for long-term storage.. b. The exact amount of propane required can also be a mystery. Make sure the tank is battery-safe.. c. Think about who you intend to use the propane for, as well as your expected income. How many gallons of propane can you purchase in a normal household? Depending on the cost of your propane tank, you will need around $12 , 000.. d. Make a list of all the things you do that are going to use propane for and then determine the range of propane usage you need. Choose a 4.7 gallon (18 l) tank for barbeque grills..
The answer is:
d.