$\mathrm{K}\to \mathrm{L}$ : Isochoric process with increasing in pressure so by $\left(\frac{{\mathrm{T}}_{\mathrm{L}}}{{\mathrm{T}}_{\mathrm{K}}}\right)=\left(\frac{{\mathrm{P}}_{\mathrm{L}}}{{\mathrm{P}}_{\mathrm{K}}}\right)$
${\mathrm{P}}_{\mathrm{L}}>{\mathrm{P}}_{\mathrm{K}}$ so ${\mathrm{T}}_{\mathrm{L}}>{\mathrm{T}}_{\mathrm{K}}$ so it is a case of heating
$\mathrm{L}\to \mathrm{M}$ : Isobaric process with increasing in pressure so by $\left(\frac{{\mathrm{T}}_{\mathrm{M}}}{{\mathrm{T}}_{\mathrm{L}}}\right)=\left(\frac{{\mathrm{V}}_{\mathrm{M}}}{{\mathrm{V}}_{\mathrm{L}}}\right)$
${\mathrm{V}}_{\mathrm{M}}<{\mathrm{V}}_{\mathrm{L}}$ so ${\mathrm{T}}_{\mathrm{M}}<{\mathrm{T}}_{\mathrm{L}}$ so it is a case of cooling
Similarly for
$\mathrm{M}\to \mathrm{N}$ : Isochoric process with increasing in pressure so by $\left(\frac{{\mathrm{T}}_{\mathrm{N}}}{{\mathrm{T}}_{\mathrm{M}}}\right)=\left(\frac{{\mathrm{P}}_{\mathrm{N}}}{{\mathrm{P}}_{\mathrm{M}}}\right)$
${\mathrm{P}}_{\mathrm{N}}<{\mathrm{P}}_{\mathrm{M}}$ so ${\mathrm{T}}_{\mathrm{N}}<{\mathrm{T}}_{\mathrm{M}}$ so it is a case of cooling