In Mendelism, linkage was not observed due to

Percentage of recombination between $A$ and $B$ is $9\%$ and $C$ is $17\%$, $B$ and $C$ is $26\%$, then the arrangement of genes is

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

Frequency of crossing over in a chromosome is an index of

Assertion : In case of incomplete linkage, linked gene show new combination along with parental combination.

Reason : In case of incomplete linkage, linked genes are separated by crossing over.

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