Final answer:
Steel alloys are commonly known to be magnetic, conductive, and elastic. They are not transparent, which is a property not associated with metals. Therefore, the shaft made of a steel alloy would have magnetic, conductive, or elastic properties.
Step-by-step explanation:
The question pertains to the properties of a steel alloy used in the construction of a shaft. Given the properties such as being shiny, malleable, ductile, conducting heat and electricity well, with variable hardness and melting temperature, it's clear that the steel alloy is not transparent. Therefore, the correct answer to the question, "A shaft is made of a steel alloy having ________ properties," is not (d) Transparent, but rather (a) Magnetic, (b) Conductive, or (c) Elastic. These are the properties typically associated with steel and other metals.
Given that steel is commonly known to be magnetic and also conducts electricity (though not as well as metals like copper), the most suitable answers would be (a) Magnetic and (b) Conductive. Since elasticity refers to the ability of a material to resume its normal shape after being stretched or compressed, this is also a property of steel alloys to varying degrees, making (c) Elastic a possible answer as well. However, option (d) Transparent is not applicable to steel alloys or most metals in general, as they are opaque materials.