Quantitative traits having low heritability are improved by using

Answer: Option B

Quantitative traits having low heritability are improved by using recurrent selection.
Recurrent selection means repeated cycles of selection and breeding aimed at gradual genetic improvement of a few key traits in a single species.
Genomic selection and marker-assisted recurrent selection have been applied to improve quantitative traits in many cross-pollinated crops.
The benefits of breeding are cumulative in that each cycle or generation of improvement builds upon advances made in prior generations.