Females heterozygous for the recessive second chromosome mutations px, sp, and cn are mated to a male homozygous for all three mutations.The offspring are as follows:
$\begin{array}{|l|r|}\hline p x  s p  c n & 1461 \\\hline p x  s p  c n^{+} & 3497 \\\hline p x  s p{+ c n} & 1\\\hline p x  s p^{+}  c n+ & 11 \\\hline p x^{+}  s p  c n & 9 \\\hline p x^{+}  s p  c n+ & 0 \\\hline p x^{+}  s p+ c n & 3483 \\\hline p x^{+}  s p+ c n+ & 1539 \\\hline & 10,000 \\\hline\end{array}$
-Which of the following linkage maps correctly shows the order and distance between the px, sp, and cn genes?

Question

Females heterozygous for the recessive second chromosome mutations px, sp, and cn are mated to a male homozygous for all three mutations.The offspring are as follows:

\begin{array}{|l|r|}\hline p x &nbsp;s p &nbsp;c n & 1461 \\\hline p x &nbsp;s p&nbsp; c n^{+} & 3497 \\\hline p x&nbsp; s p{+&nbsp;c n} & 1\\\hline p x&nbsp; s p^{+}&nbsp; c n+ & 11 \\\hline p x^{+} &nbsp;s p &nbsp;c n & 9 \\\hline p x^{+} &nbsp;s p &nbsp;c n+ & 0 \\\hline p x^{+}&nbsp; s p+&nbsp;c n & 3483 \\\hline p x^{+}&nbsp; s p+&nbsp;c n+ & 1539 \\\hline & 10,000 \\\hline\end{array}

-Which of the following linkage maps correctly shows the order and distance between the px, sp, and cn genes?