Consider the expression $(a-1) * (((b+c) / 3)) + d))$. Let $\text{X}$ be the minimum number of registers required by an optimal code generation (without any register spill) algorithm for a load/store architecture, in which
- only load and store instructions can have memory operands and
- arithmetic instructions can have only register or immediate operands.
The value of $\text{X}$ is _____________ .
- $2$
- $1$
- $4$
- $3$
