A. Malteses, which originated in south central Europe, have long been
a prized dog when
Use of "them" in the non-underlined portion of the sentence implies that "Malteses" is plural. Hence the use of singular "a prized dog" is
INCORRECT___________________________________
B. Malteses, originating in south central Europe, have long been prized dogs
to The presence of "to" makes the "ancient Egyptians" part of the first clause and hence the second clause is missing a subject
INCORRECT___________________________________
C. Originated in south central Europe, Malteses have long been
a prized dog;
Use of "them" in the non-underlined portion of the sentence implies that "Malteses" is plural. Hence the use of singular "a prized dog" is
INCORRECT___________________________________
D. Originating in south central Europe, Malteses have long been prized dogs;
"Originating in south central Europe" correctly modifies Malteses. The presence of ";" correctly splits the sentence into two clauses.
CORRECT___________________________________
E. Malteses
originate in south central Europe;they also have long been prized dogs when
Meaning error. Use of simple present in the first clause changes meaning.
INCORRECT___________________________________
Hence option D