Which of the following statements best describes mechanism of action of benzodiazepines -

• A. Benzodiazepenes activate GABA (B) receptors in the spinal cord
• B. Their inhibition of GABA transaminase leads to increased levels of GABA
• C. Benzodiazepenes block glutamate receptors in hierarchical Neural pathways in the br
• D. They increase the frequency of opening of chloride ion channels that are coupled to GABA (A) receptors