In Drosophila, long wing and broad abdomen characters are dominant over to characters vestigeal wing and narrow abdomen. A pure breeding Drosophila having long wings and broad abdomen is crossed with a pure breeding vestigeal-winged and narrow-abdomened Drosophila. Two of the $F_1$ individuals were crossed and the following results were produced in the $F_2$ generation Long wing, broad abdomen in $482$ Drosophila. Vestigeal wing, narrow abdomen in $154$ Drosophila. Which one of the following is illustrated by these results

Select the correct statement from the ones given below with respect to dihybrid cross.

The map distance between genes $A$ and $B$ is $3$ units, between $B$ and $C$ $10$ units and between $C$ and $A$ $7$ units. The order of the genes in a linkage map constructed on the above data would perhaps be

$A$ : Crossing over is exchange of genetic material between non-homologous chromosomes.
$R$ : It produces new linkages.

$A$ : Morgan's cross III was conducted in Drosophila to locate genes on chromosome for white eye colour.
$R$ : The cross was done between red eyed hybrid female and white eyed male.