Solution

Correct Answer: (iv) linear model and Prototyping model

Explanation

Incremental Model delivers system in increments (builds).

• Linear model (Waterfall) provides sequential phases (requirements→design→code→test) for each increment.
• Prototyping provides iterative feedback and early versions for each increment before final integration.

So each increment follows linear sequence, but overall product evolves via prototypes/increments.

Why others wrong:

• (i) Build-and-Fix is ad-hoc, not a model
• (ii) RAD is itself an incremental/high-speed variant, not parent
• (iii) Waterfall + RAD is redundant (RAD already contains incremental)

Answer: (iv) linear model and Prototyping model