The correct option is C CIF3<PF3<BF3
The bond angle in BF3 is 120∘ since B is sp2 - hybridized. In PF3, P is sp3 - hybridized but the bond angle is little less that 109∘.28′ (but far greater than 90∘) due to bond pair - lone pair repulsion. In CIF3, Cl is sp3 d hybridized. It has T - shape and hence the bond angle is around 90∘. Therefore the correct order of increasing bond angle is CIF3<PF3<BF3