• Symmetry in Nematode Anatomy:
• Lip Region (Cephalic Apex): Statement (I) is correct because the ancestral nematode head has hexaradial symmetry, featuring 6 lips (2 subdorsal, 2 subventral, and 2 lateral) surrounding the oral aperture, each bearing cephalic sensilla.
• Esophagus (Pharynx): Statement (II) is correct because the nematode esophagus exhibits triradial symmetry, consisting of a cuticular lumen with three branches (one dorsal and two ventrolateral sectors) containing radially arranged muscle fibers.
• Conclusion: Both Statement (I) and Statement (II) are correct (Option 1).

• Contents of the Nematode Pseudocoelom:
• Statement (I) is correct: The spacious pseudocoelomic cavity houses the tubular reproductive system (testes, vas deferens in males; ovaries, oviducts, and uterus in females), which floats suspended within the pseudocoelomic fluid.
• Statement (II) is correct: Major components of the nervous system (including the circumesophageal nerve ring, nerve cords running in hypodermal chords, and ganglionic cell bodies) and excretory renette cells are situated in or directly project into the pseudocoelom.
• Conclusion: Both Statement (I) and Statement (II) are correct (Option 1).

• Standard Tyler / US Sieve Series Aperture Sizes:
• Conversion Formula: Mesh number refers to the number of openings per linear inch ($25.4\text{ mm}$):

• Standard Values for Nematode Extraction Sieves:
• 20 mesh: $850\,\mu\text{m}$
• 60 mesh: $250\,\mu\text{m}$
• 100 mesh: $150\,\mu\text{m}$
• 200 mesh: $75\,\mu\text{m}$
• 300 mesh: $53\,\mu\text{m}$
• 350 mesh: $45\,\mu\text{m}$ (nominal standard aperture $44-45\,\mu\text{m}$)
• 400 mesh: $38\,\mu\text{m}$
• Conclusion: The aperture size of a 350 mesh sieve is $45\,\mu\text{m}$ (Option 2).

Correct option: (2) 45um