Agas changes directly to a solid during(1) fusion (3) saponification(2) deposition (4) decomposition

Answer is: deposition.

Deposition is a thermodynamic process in which gas transforms into solid without passing through the liquid phase.  

For example, forming snow in clouds directly from water vapor.

During deposition phase change, energy is released.  

Another example, the phase change H₂(g) → H₂(s) is called deposition and the enthalpy change, ΔH, for this phase change has a negative (-) sign.