Carbon nanotubes can be a considered toxic agent due to: (a) - Its ability to produce toxic gases (b) Its ability to penetrate skin quickly due its very small diameter (c) Its ability to mix with water (d) Difficulties in handling it properly

Answer: b) Its ability to penetrate skin quickly due to its very small diameter

Explanation: Carbon nano tubes (CNT) are the material widely used in the medical field due to the atomic structure of it ans also have small size. Toxicity in the carbon nano tubes is because their small sized atomic particles which can enter the skin by penetration or inhalation. But are still preferred in the medicine because having unique properties like mechanical property, chemical property, surface property etc.