If Mutagenizing a Number of Drosophila Results in Several Observable

Multiple Choice

If mutagenizing a number of Drosophila results in several observable phenotypes but also in several lethal mutations,does this mean that recessive lethal mutations cannot be studied further?

A) No;the lethal allele can be recovered from heterozygous siblings.
B) No;the lethal alleles can be sequenced from the other embryos.
C) Yes;lethal alleles can be studied only if they are recessive.
D) Yes;lethal alleles can be studied only if they are conditional.
E) Yes;unless the lethal allele can be supplemented with a missing gene product.