Principle involved

In both TLC and column chromatography using silica gel as stationary phase:

• Silica gel is polar.
• Less polar compounds interact less with silica and move faster.
• More polar compounds interact more strongly and move slower.

Relation between TLC and column chromatography

In TLC on silica:

• Higher spot on the plate $\Rightarrow$ larger $R_f$ value $\Rightarrow$ weaker adsorption on silica $\Rightarrow$ less polar.
• Lower spot on the plate $\Rightarrow$ smaller $R_f$ value $\Rightarrow$ stronger adsorption on silica $\Rightarrow$ more polar.

In silica gel column chromatography:

• The compound with largest $R_f$ in TLC elutes first.
• The compound with smallest $R_f$ elutes last.

Reading the TLC observation

From the given TLC figure, the spots are ordered by height as:

$A \text{ highest},\quad C \text{ middle},\quad B \text{ lowest}$

Therefore,

$R_f(A) > R_f(C) > R_f(B)$

Convert this to order of elution in silica gel column

Since higher $R_f$ means earlier elution:

$A \text{ elutes first},\quad C \text{ second},\quad B \text{ last}$

So the elution order is:

$A,\ C,\ B$

Check options

• A: $B, A, C$ ❌
• B: $C, A, B$ ❌
• C: $A, C, B$ ✅
• D: $B, C, A$ ❌

Comparison with stored answer

Our derived answer is Option C.

Stored correct answer is also C.

Hence, they agree.