Statements: • Some tyres are rains. • Some rains are flowers. • All flowers are jungles. • All jungles are tubes. Conclusions: I. Some jungles are tyres. II. Some tubes are rains. III. Some jungles are rains. IV. Some tubes are flowers. Choose the option that must follow.

Introduction / Context:
Two universal steps push existence from Flowers onward to Jungles and Tubes. We test which intersections are forced by these inclusions.

Given Data / Assumptions:

• ∃r_f ∈ Rains ∩ Flowers.
• Flowers ⊆ Jungles ⊆ Tubes.
• ∃t_r ∈ Tyres ∩ Rains (may be different from r_f).

Concept / Approach:
From r_f ∈ Flowers and Flowers ⊆ Jungles, r_f ∈ Jungles. Hence Jungles ∩ Rains ≠ ∅ (III). Also, since Jungles ⊆ Tubes, r_f ∈ Tubes, so Tubes ∩ Rains ≠ ∅ (II) and Tubes ∩ Flowers ≠ ∅ (IV). There is no forced link between Tyres and Jungles, so I is not necessary.

Step-by-Step Solution:
1) Push r_f through universals: Flowers → Jungles → Tubes.2) Record intersections: Jungles ∩ Rains (III), Tubes ∩ Rains (II), and Tubes ∩ Flowers (IV) are all guaranteed.3) For I, we would need the Tyres∩Rains witness to be the same as the Rains∩Flowers witness; not required.

Verification / Alternative check:
Model Tyres∩Rains disjoint from Flowers. Then II–IV still hold via the flower-rain element, while I fails.

Why Other Options Are Wrong:
They include I, which is not forced.

Common Pitfalls:
Equating different “some” witnesses.

Final Answer:
Only II, III and IV follow.