Our biggest concern is the rising cost/costs of food.

[teacherjapan]

Which would be a better choice, costs or cost in the following example?

Our biggest concern is the rising cost/costs of food.

 

[SoothingDave]

Cost

 

[emsr2d2]

To use "costs", say "Our biggest concerns are the rising costs of food".

 

[SoothingDave]

I don't even like that. If costs are going to be plural, I would want the object to also be plural. Like "the rising costs of various food items."