Answer:
B. metalloids
Step-by-step explanation:
The metalloids are found between metals and non-metals on the periodic table.
Metalloids have properties between those of metals and non-metals. Under certain prevalent conditions, they exhibit a set of properties.
Synthetic substances are those artificially made, they are not found on the periodic table.
Noble gases are found in the last group on the periodic table.
Radioactive substances are found in the lanthanide and actinide series.