Antihistamines are drugs that are used to treat allergic rhinitis (both seasonal and perennial) and other form of allergies that cause hives or urticaria. They can give relief when a patient has nasal congestion, sneezing or hives because of pollen, dust, or animal allergy (allergens). Second generation antihistamines such as loratidine are prescribed for seasonal allergies because they are less sedating than the first generation antihistamines.
I would say the first option
Answer:
this is because Steel is more difficult to magnetise and demagnetise but an iron core makes a temporary electromagnet because its lose its magnetism when the switch is open and and steel core is used to make a permanent electromagnet
