Answer:
The trait is Y-linked
Explanation:
The only plausible explanation behind the inheritance pattern shown by the porcupine trait is that it is Y-linked.
Y-linked traits are limited to the Y chromosome only, a sex chromosome that is peculiar to only the male gender. Chromosomally, females are XX while males are XY. Hence, only the male gender has the genetic capacity to inherit the porcupine trait. This is why only the sons of Edward Lambert, and never the daughters, exhibited the trait.