To solve this problem, we need to analyze the events that occur during muscular contraction. Let's examine each statement:$\newline \bullet$(a) ‘H’ zone disappears:$\newline$ - During muscle contraction, the actin filaments slide over the myosin filaments, causing the ‘H’ zone, which is the region of the A band where there is no overlap between actin and myosin, to disappear.$\newline$ - This statement is correct.$\newline \bullet$(b) ‘A’ band widens:$\newline$ - The ‘A’ band represents the length of the myosin filaments and does not change in width during contraction.$\newline$ - This statement is incorrect.$\newline \bullet$(c) ‘I’ band reduces in width:$\newline$ - The ‘I’ band is the region containing only actin filaments. As the actin slides over the myosin, the ‘I’ band shortens.$\newline$ - This statement is correct.$\newline \bullet$(d) Myosine hydrolyzes ATP, releasing the ADP and Pi:$\newline$ - Myosin heads hydrolyze ATP to provide the energy required for muscle contraction, releasing ADP and inorganic phosphate (Pi).$\newline$ - This statement is correct.$\newline \bullet$(e) Z-lines attached to actins are pulled inwards:$\newline$ - During contraction, the Z-lines, which are the boundaries of a sarcomere, are pulled closer together as the actin filaments slide inward.$\newline$ - This statement is correct.$\newline$Based on the analysis, the correct events that occur during muscular contraction are:$\newline$(a), (c), (d), and (e).$\newline$Therefore, the correct answer is Option 1: (a), (c), (d), (e) only.