Step 1: Understand the matching.
We must pair each Lok Sabha term (a) XIth, (b) XIVth, (c) XVth, (d) XVIth with its Speaker.
Step 2: Match the XIth Lok Sabha.
P. A. Sangma served as Speaker of the XIth Lok Sabha, giving $a \rightarrow IV$.
Step 3: Match the XIVth Lok Sabha.
Somnath Chatterjee was Speaker during UPA-1, giving $b \rightarrow III$.
Step 4: Match the XVth Lok Sabha.
Meira Kumar, the first woman Speaker, headed the XVth Lok Sabha, giving $c \rightarrow II$.
Step 5: Match the XVIth Lok Sabha.
Sumitra Mahajan was Speaker of the XVIth Lok Sabha, giving $d \rightarrow I$.
Step 6: Assemble and select.
The set $a\text{-}IV, b\text{-}III, c\text{-}II, d\text{-}I$ is option B.
\[ \boxed{a\text{-}IV,\ b\text{-}III,\ c\text{-}II,\ d\text{-}I} \]