Ok , so the carpet installer guy is here . He saw our wedding picture and said he liked Marty 's kilt and said the next time he gets married he 's wearing one . I asked if he was Scottish . He said , " Irish " and then proceeded to lift up his shirt to show me a full back tattoo of celtic cross with sword in the middle .

pick from the following.
[a]. The Celtic cross expresses his religious fervor .
[b]. The Celtic cross is considered a Scottish symbol .
[c]. The Celtic cross denotes his families heritage .
[d]. The Celtic cross is aesthetically pleasing to the Scottish .
Answer the following question: Why would the carpet installer choose to tattoo a Celtic cross on his back ?
[c].