The correct order of first ionization enthalpy for the given four elements is :

Decrease in size from left to right in actinoid series is greater and gradual than that in lanthanoid series due to

Fluorine is a stronger oxidising agent than chlorine because :

(a) F-F bond has a low enthalpy of dissociation.

(b) Fluoride ion (F^$$-$$) has high hydration enthalpy.

(c) Electron gain enthalpy of fluorine is less negative than chlorine.

(d) Fluorine has a very small size.

Choose the most appropriate answer from the options given :

If first ionization enthalpies of elements X and Y are 419 kJ mol^$$-$$1 and 590 kJ mol^$$-$$1, respectively and second ionization enthalpies of X and Y are 3069 kJ mol^$$-$$1 and 1145 kJ mol^$$-$$1, respectively. Then correct statement is :