When checking tires, finding which of the following is not a cause for concern?

Question

When checking your vehicle's tires, you should confirm that air pressure is neither too low nor too high; that there is at least 4/32 of an inch of tread depth in every major groove on the front tires; and that radial and bias-ply tires are not used together.

Accepted Answer

Tread of at least 4/32 of an inch in the grooves on front tires

Answer

Too much air pressure

Answer

Radial and bias-ply tires used together