What would happen if blocking tags were NOT used in reversible terminator sequencing, a next-generation method of DNA sequencing?

A) The DNA fragments to sequence/read would be too large.
B) More than one dNTP could be incorporated to the same growing nucleotide chain during a single cycle.
C) The flow cell could not immobilize DNA fragments.
D) Multiple fluorescent colors could be observed across the flow cell at the same time.
E) Luciferase would not react in the presence of ATP.