Final answer:
Elements 19-36 on the periodic table are all in the same row. Therefore, the correct option is A.
Step-by-step explanation:
Elements 19 through 36 are all located in the same row in the periodic table. This elemental block, which runs from potassium (K) to krypton (Kr), is part of the fourth period. The horizontally organized rows in the periodic table, commonly referred to as periods, stand in for the energy levels or electron shells of individual atoms.
All elements in a row have the same atomic structure, but the elements after it have one extra proton in their nucleus. As a result of the growing number of electron shells, elements in the same row of the periodic table have distinguishing properties, whereas columns in the table, referred to as groups or families, have comparable chemical properties.
Therefore, the correct option is A.