Match the following control strategies of protocol $:$
$\begin{array}{} & \textbf{List – I} && \textbf{List – II} \\ \text{a.} & \text{Forward movement} & \text{i.} & \text{Variable can be done with a constant,}\\ &&& \text{another variable or a function} \\ \text{b.} & \text{Unification} & \text{ii.} & \text{The entire conjunctive goal is executed} \\ \text{c.} & \text{Deep back-tracking} & \text{iii.} & \text{Previous sub goal to find alternative } \\ &&& \text{solutions} \\ \text{d.} & \text{Shallow back-tracking} & \text{iv.} & \text{Chooses sub goal with possible unifier} \\ \end{array}$
$\textbf{Codes :}$
- $\text{a-iv, b-i, c-ii, d-iii}$
- $\text{a-ii, b-iv, c-i, d-iii}$
- $\text{a-iii, b-i, c-iv, d-ii}$
- $\text{a-ii, b-iii, c-iv, d-i}$
