Step 1: Understanding the Concept:
According to VSEPR theory, a molecule has a "regular geometry" if the central atom has no lone pairs and is bonded to identical surrounding atoms.
Step 2: Key Formula or Approach:
Check for lone pairs on the central atom:
Lone pairs $= \frac{1}{2}[\text{Valence } e^- - \text{shared } e^-]$.
Step 3: Detailed Explanation:
(A) $\text{SiCl}_4$: Si has 4 valence electrons, all used in bonding with 4 Cl atoms. Lone pairs $= 0$. Geometry is regular tetrahedral.
(B) $\text{SF}_4$: S has 6 valence electrons. 4 are used for bonding, leaving 1 lone pair. Geometry is distorted (see-saw).
(C) $\text{BrF}_5$: Br has 7 valence electrons. 5 are used for bonding, leaving 1 lone pair. Geometry is distorted (square pyramidal).
(D) $\text{XeF}_4$: Xe has 8 valence electrons. 4 are used for bonding, leaving 2 lone pairs. Geometry is distorted (square planar).
Step 4: Final Answer:
$\text{SiCl}_4$ has a regular geometry.