What items are included as military demolition blocks and blasting caps in Category IV(a)?

The correct choice encompasses electric squibs and seismograph electric blasting caps, which fall under the definition provided in Category IV(a) for military demolition. Electric squibs are small devices used to initiate explosives, and seismograph electric blasting caps are specifically designed to detonate explosives while simultaneously recording seismic activity. Both of these items are crucial in military operations where precise detonation is necessary, and they adhere to the specifications outlined for this category.

Other options include items that are not exclusively categorized within military demolition blocks and blasting caps. TNT and detonation cords serve different purposes in demolition but do not specifically fit the criteria for Category IV(a). Similarly, hand grenades and M67 explosives are classified differently due to their intended use as munitions rather than demolition equipment. Non-electric detonators, while related to blasting and explosives, do not meet the necessary classifications found in the specifics of this category.