Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| District | Incumbent | Party | First elected | Result |
| --- | --- | --- | --- | --- |
| South Carolina 1 | George Swinton Legaré | Democratic | 1902 | Re-elected |
| South Carolina 2 | James O'H. Patterson | Democratic | 1904 | Lost primary Democratic hold |
| South Carolina 3 | Wyatt Aiken | Democratic | 1902 | Re-elected |
| South Carolina 4 | Joseph T. Johnson | Democratic | 1900 | Re-elected |
| South Carolina 5 | David E. Finley | Democratic | 1898 | Re-elected |
| South Carolina 6 | J. Edwin Ellerbe | Democratic | 1904 | Re-elected |
| South Carolina 7 | Asbury F. Lever | Democratic | 1901 (special) | Re-elected |
Question:
Which district has joseph t. johnson as an incumbent?
Answer:
South Carolina 4