From among the choices provided, the more appropriate
answer is ' T ', the initial letter often used to represent
words that include 'true', 'truth', 'trust', etc., (as well as
'tree', 'train', 'transmit', 'Transylvania', 'trachea', 'travesty',
and 'trick', which are irrelevant to the present discussion).
This response is the most fitting and appropriate, because
the statement that precedes the list of allowable choices is
exemplary in its accuracy and veracity. An ion can, in fact,
have a positive or negative charge, although the same ion
cannot have both.