Final answer:
Iron, the option c), is the element from the choices given that belongs to the d-block of the periodic table, which is known for transition metals.
Step-by-step explanation:
Out of the options given, c) Iron is the element that belongs to the d-block of the periodic table. The d-block consists of the transition metals, which are located in the center of the periodic table, spanning groups 3-12. Iron falls into this category and is found in group 8. It is characterized by its ability to form various oxidation states and its magnetic properties.
Hydrogen (a) belongs to Group 1 but is not a d-block element. Oxygen (b) is a chalcogen and a part of the p-block, whilst Helium (d) is a noble gas, also located in the p-block of the periodic table. Therefore, the correct answer is c) Iron.