Final answer:
An NFA (Non-deterministic Finite Automaton) must have a single unique start state. Multiple start states are not allowed as it contradicts the definition and construction rules of an automaton in automata theory.
Step-by-step explanation:
In the field of Computers and Technology, specifically in the area of formal languages and automata theory, an NFA, which stands for Non-deterministic Finite Automaton, is a theoretical machine used to recognize patterns. By definition, an NFA is allowed to have non-deterministic transitions, which means it can have multiple transitions for a given input symbol from a single state. However, it cannot have multiple start states; it must have a single unique start state. This is because the start state serves as the point of entry into the system, and having more than one would violate the definition of an NFA and the rules of automaton construction.