NEET UG BIOLOGY MCQ: PRINCIPLE OF INHERITANCE AND VARIATION

An individual homozygous for genes $\text{cd}$ is crossed with wild type and $F_1$ crossed back with
the double recessive. The appearance of the offspring is as follows.
$\begin{array}{cccccccccccccccccccc} { + + }& \to &{903} \\ {{\text{cd}}}& \to &{897} \\ { + {\text{d}}}& \to &{98} \\ {{\text{c}} + }& \to &{102} \end{array}$
The distance between the genes $\text{c}$ and $\text{d}$ is