Which of the following statements is true about Parthenium (carrot grass)?

All of the above statements are true.

a- Parthenium has become widely distributed and occurs ubiquitously.

b- Parthenium causes pollen allergy.

c-Parthenium was introduced to India as a contaminant along with imported wheat.

The correct answer is (d) All of the above statements are true.

(a) It has become ubiquitous in occurrence: Parthenium has rapidly spread and become widely distributed in India. It has adapted well to different climatic conditions and is commonly found in various habitats such as agricultural fields, roadsides, wastelands, and disturbed areas. Its ability to produce a large number of seeds and adapt to different environments has contributed to its widespread occurrence.

(b) It causes pollen allergy: Parthenium is known to cause allergic reactions, particularly through its pollen. Many individuals are sensitive to Parthenium pollen, and exposure to it can lead to symptoms such as respiratory allergies, skin rashes, and asthma. The release of Parthenium pollen into the air during flowering season can result in significant health issues for people who are allergic to it.

(c) Parthenium came into India as a contaminant with imported wheat: Parthenium, also known as carrot grass or congress grass, was introduced to India as a contaminant along with imported wheat. It is believed that the seeds of Parthenium were unintentionally mixed with wheat seeds during importation.

Therefore, all of the statements about Parthenium are correct. It arrived in India as a contaminant with imported wheat, it has become ubiquitous in occurrence, and it is known to cause pollen allergy.