How does a mortar hoe differ from a traditional garden hoe?

A mortar hoe is specifically designed for the mixing and manipulation of mortar, and its unique feature is indeed the presence of two holes in its head. These holes serve a functional purpose: they allow for better mixing of mortar by facilitating the incorporation of air into the mix and helping to break up clumps of material. This design improves the efficiency of mixing and makes the tool more effective for masonry work as compared to a traditional garden hoe, which typically has a solid, flat blade without these holes.

In contrast, the other options do not accurately describe the distinguishing features of a mortar hoe. For instance, while it's possible for mortar hoes to have varying handle lengths, they are not universally longer than garden hoes. Additionally, the head of a mortar hoe does not necessarily have a wider dimension; its design focuses more on the functional attributes necessary for mixing mortar rather than breadth. Lastly, while tools can be made from various materials, mortar hoes are traditionally constructed from metal for durability, whereas a plastic alternative would not provide the required strength and weight for effective mixing. This is particularly important in masonry, where robust tools are essential for handling heavy materials.