(B) (i) and (iv)
Swimming technique and dancing skills are acquired traits (learned through practice) and cannot be transmitted genetically to offspring.
The key concept here is the difference between inherited traits (determined by genes, e.g., blood group, eye colour) and acquired traits (skills learned during one's lifetime, e.g., swimming, dancing). Acquired traits do not cause changes in DNA/genes and therefore cannot be passed on to offspring. Blood group and eye colour are genetically determined and are heritable.