Which of the following is a weak field ligand?

Given below are two statements:
Statement $I$: Presence of a large number of unpaired electrons in transition metal atoms results in higher enthalpies of their atomisation.
Statement $II$: $d_{xy} = d_{xz} = d_{yz} < d_{x^2-y^2} = d_{z^2}$ and $d_{x^2-y^2} < d_{xy} = d_{xz} = d_{yz}$ are the $d$-orbital splittings in $[Fe(H_2O)_6]^{3+}$ and $[Ni(Cl)_4]^{2-}$ complex ions respectively.
In the light of the above statements, choose the correct answer from the options given below:

The $3d$ metal ions form coloured compounds because the energy corresponding to the following lies in the visible range of the electromagnetic spectrum:

The number of unpaired electrons in the complex ion $[CoF_6]^{3-}$ is (Atomic number of $Co = 27$).

Which sets of the $d$-orbitals are directly oriented towards the ligands in octahedral coordination compounds?

The octahedral complex of a metal ion $M^{3+}$ with four monodentate ligands $L_1, L_2, L_3$ and $L_4$ absorb wavelengths in the region of red,green,yellow and blue,respectively. The increasing order of ligand strength of the four ligands is: