Answer:
D. Verbal, Informal.
Explanation: An oral report clearly exemplifies verbal communication and it would be Informal as this is an oral report contrary to the formal which is a written document perhaps, it may be formal too as it moves through a pre-defined channel.But, an oral report would be best cited as an example of Informal verbal communication as it is Non-written, having a chance to move freely, Quick Yet Non-Worthy and less reliable as compared to formal one.