Consider we have loaded our data frame, named NBA, using the data in the file below. Write a single statement that can find a number of unique playing positions? Name Тeam Number Position Age Height...

Extracted text: Consider we have loaded our data frame, named NBA, using the data in the file below. Write a single statement that can find a number of unique playing positions? Name Тeam Number Position Age Height Avery Bradley Boston Celtics PG 25 6-2 Jae Crowder Boston Celtics 99 SF 25 6-6 John Holland Boston Celtics 30 SG 27 6-5 RJ. Hunter Boston Celtics 28 SG 22 6-5 Jonas Jerebko Boston Celtics 8 PF 29 6-10 Amir Johnson Boston Celtics 90 PF 29 6-9 Jordan Mickey Boston Celtics 55 PF 21 6-8 Kelly Olynyk Boston Celtics Terry Rozier Boston Celtics 41 25 7-0 12 PG 22 6-2 Marcus Smart Boston Celtics 36 PG 22 6-4 Jared Sullinger Boston Celtics 7 24 6-9 Isaiah Thomas Boston Celtics 4 PG 27 5-9 Evan Tumer Boston Celtics 11 SG 27 6-7 O a. NBA [Position].unique () O b. NBA.position.unique () O . NBA[ 'Position'].unique () O d. NBA. Position.notRepeat()