The correct option is ( D )
Explanation.
.A uniform linear array can be Broadside array or End fire array.
Broadside array is an array of elements for which radiation is max or main lobe occurs perpendicular to the axis of the array.
End fire array is an array of elements for which main beam occurs along the axis of array.
For broadside array
Null to Null beam width = 2λ/N.d
For End fire array = 2 √2λ/Nd
Where N = No. of antennas in the array
d = spacing between elements
Beam width for both the arrays is determined by the product