Which route should I take from Nanchong to Beijing?

There is no direct train from Nanchong to Beijing. The trains arriving via transfer are as follows:

Option 1 Nanchong->Dazhou->Beijing West (the most economical trip)

Departure from Nanchong, arrival in Dazhou, travel time, travel distance, fare in this range

5642/5643 (Chengdu--Wanzhou) 17:22 19:54 2 hours, 32 minutes 159 12

Transfer train departs from Dazhou and arrives at Beijing West. Travel time, travel distance, fare in this range

1390 (Chongqing--Beijing West) 00:15 05:42 1 day, 5 hours, 27 minutes 1832 171

Option 2 Nanchong->Wuchang->Beijing West (shortest travel time)

Departure from Nanchong to Wuchang travel time travel distance fare in this range

T248/T245 (Chengdu--Wuchang) 17:58 08:12 14 hours 14 minutes 1137 146

Transfer train departs from Hankou and arrives at Beijing West Travel Time Travel Distance Fare in this range

D122 (Hankou --Beijing West) 11:05 19:27 8 hours and 22 minutes 1205 373

Option 3 Nanchong->Ankang->Beijing West (the shortest travel distance)

The departure train departs from Nanchong Travel time to Ankang, travel distance, fare in this range

T126/T127 (Chengdu--Dongguan East) 01:31 08:23 6 hours 52 minutes 435 65

Transfer train departs from Ankang Arrival in Beijing West Travel Time Travel Distance Fare in this range

1364 (Chengdu - Beijing West) 10:48 05:49 19 hours 1 minute 1459 137