The shape of PCl3 molecule is:
A. trigonal bipyramid
B. tetrahedral
C. pyramidal
D. square planar

To determine the shape of the PCl₃ (phosphorus trichloride) molecule, we can use the Valence Shell Electron Pair Repulsion (VSEPR) theory, which helps predict the geometry of molecules based on the repulsion between electron pairs around a central atom.

### Steps to Solve:

1. **Count Valence Electrons**:
- Phosphorus (P) has 5 valence electrons.
- Each chlorine (Cl) atom has 7 valence electrons, and there are three Cl atoms, contributing \(3 \times 7 = 21\) valence electrons.
- Total valence electrons = \(5 + 21 = 26\).

2. **Determine the Central Atom**:
- Phosphorus is the central atom since it can form multiple bonds.

3. **Draw the Lewis Structure**:
- Place the three Cl atoms around the P atom.
- Connect each Cl to P with a single bond. This uses \(3 \times 2 = 6\) electrons (3 bonds).
- The remaining electrons \(26 - 6 = 20\) will be used to satisfy the octet rule for the Cl atoms. Each Cl will have 3 lone pairs, consuming 18 electrons (6 pairs).
- The phosphorus atom will have one lone pair left since it can expand its octet (it has access to d-orbitals), which consumes the remaining 2 electrons.

4. **Identify the Number of Bonding and Lone Pairs**:
- P has three bonded pairs (to the three Cl atoms) and one lone pair.
- This gives a total of \(3 + 1 = 4\) regions of electron density.

5. **Determine the Molecular Shape**:
- With four regions of electron density, the electron geometry is tetrahedral.
- However, because there is one lone pair, the molecular geometry is trigonal pyramidal (like a pyramid with a triangular base), as the lone pair occupies one of the tetrahedral positions.

### Conclusion:
Given this analysis, the correct shape of the PCl₃ molecule is **C. pyramidal** (specifically, trigonal pyramidal).