Hemophilia is an x-linked recessive disease. under which of the following conditions will a female child inherit hemophilia? both parents must have the hemophilia allele. only the father must have the hemophilia allele. both sets of grandparents must have the hemophilia allele. only the mother must have the hemophilia allele.

I believe the correct answer is the first option: Both parents must have the hemophilia allele.

Hemophilia is an X-linked recessive disease, which means that hemophilia is transmitted through the X sex chromosome. The female child gets an X chromosome from her mother and an X chromosome from her father. The X chromosome from her mother is dominant and If we suppose that mother has the gene for normal blood clotting and the X chromosome from her father has the gene for hemophilia, the female child won’t have hemophilia, but will be a carrier, which means that her children will have 50% chances of inheriting hemophilia. Since females have XX chromosomes, to have hemophilia manifested, both parents must have hemophilia.

to eliminate ambiguous remote or broad reference it is necessary to focus on anaphoric reference. by definition "anaphoric reference means that a word in a text refers back to other ideas in the text for its meaning." the references should be clear and leave no room for ambiguity.

in the first case the pronoun it probably refers to the car but it has not been mentioned before so we should replace it for the car. in doing so the statement becomes clear.

in sentence number   two   the pronoun he refers to charles dickens the author. yet, the first half of the sentence is about the book a tale of two cities. to repair this it would be better to rephrase the first half : after i read   a tale of two cities by dickens, he so as to remove the remote reference.