. Performing a complementation test through cotransduction using
mutant phage genomes created by X-ray mutagenesis (mutants a-e), as
well as ones created by chemical mutagenesis using EMS (mutants
1-5), you get the following results:

1          2
   3    4 5

      a    — +
   + — —

      b    — +
   — — —

      c   
+   + — — +

      d    +
   — +    +    —

      e     — —
+    + —

Explain this data.

Hint: X-rays create DNA breaks that lead to deletions, and
chemical mutagens such as EMS result in point mutations.