THE MAXIMUM TIME DURING WHICH A S TIMULUS OF ONE RHE OBASE MUST ACT IN ORDER TO C AUSE EXCIT EMENT IS CALLED chronaxie reaction time useful time electrotone

## Step 1<br />The problem is asking for the term that describes the maximum time during which a stimulus of one type must act in order to cause excitement. This is a concept in neurophysiology, specifically in the study of nerve impulses and their effects.<br /><br />## Step 2<br />The term "chronaxie" is the correct answer. It refers to the minimum duration of a stimulus that is required to produce a response in a nerve or muscle. This term is used in the context of nerve impulses and their effects.<br /><br />## Step 3<br />The other options, "reaction time", "useful time", and "electrotone", do not accurately describe the concept in question. "Reaction time" refers to the time taken to respond to a stimulus, but it does not specify the maximum duration of the stimulus itself. "Useful time" is a general term that does not specifically relate to nerve impulses or their effects. "Electrotone" is not a recognized term in this context.