Relation between gain and effective aperture is given by _____?

• A. G=(4‚âà√¨‚àö√ëAe)/‚âà√≠¬¨‚Ñ¢2
• B. G=(4‚âà√¨‚àö√ë ‚âà√≠¬¨‚Ñ¢2)/ Ae
• C. G=4‚âà√¨‚àö√ëAe
• D. G=Ae/‚âà√≠¬¨‚Ñ¢2