The carry propagation delay in 4-bit full-adder circuits ____________.

• is normally not a consideration because the delays are usually in the nanosecond range
• is cumulative for each stage and limits the speed at which arithmetic operations are performed
• decreases in direct ratio to the total number of full-adder stages
• increases in direct ratio to the total number of full-adder stages, but is not a factor in limiting the speed of arithmetic operations