Answer:
d- the
Step-by-step explanation:
In the phrase ,The wingspan, the definite article refers specifically to the condor's wingspan. If we say: "Big birds' wingspans have different lenghts", we are generalising our idea of wingspans . We are talking about the wingspans of birds in general, so we are not using the . But, if we want to talk about a bird in particular, we have to make the information definite and use the definite article.